The mother of the woman police say was slain by accused "Craigslist killer" Philip Markoff said today her family is "devastated" by her death, but is pleased that the alleged killer won't be able to do "this horrible thing" to any other women.

Carmen Guzman, mother of Julissa Brisman, issued her heart rending statement on what would have been her daughter's 26th birthday.

The statement came hours after ABC News revealed that Markoff had scratches on him at the time of his arrest and that his fingerprints were found on plastic restraints at the scene of two of the three suspected Craigslist victims.

Markoff's prints were also found on the wall of a Warwick, R.I., hotel room where a third woman was robbed by a man believed to have chosen his victims from Craigslists ads offering erotic services, sources told ABC News.

Sources said investigators were also able to track Markoff's cell phone calls to the crime scenes. The suspect in the Rhode Island robbery was caught on surveillance cameras looking at his cell phone as he left the hotel.

Markoff, 23, is being held in a Boston jail on suicide watch. He is charged with Brisman's murder and the robbery of a second woman in Boston. Sources told ABC News he is expected to be charged with the Rhode Island robbery on Saturday.

"Our family has been devastated by the loss of our beautiful daughter, Julissa," Guzman said in her statement. "We are a close family, and Julissa called us every day. We won't be getting those calls anymore."

Investigators believe Brisman and the other two alleged

"I feel very much relieved that the man who did this is in custody and will not be able to do this horrible thing to another family," she said.

Guzman said her daughter was studying to be a counselor. "Over the past few days, people have told us the many ways in which Julissa helped them... These words mean so much to us," she said.

"We will hold Julissa in our hearts every day," she added.

The evidence against Markoff is coming to light as he was put on a suicide watch. He was moved from the general population of Boston's Nashua Street jail to a segregated unit where officers can keep a constant eye on him, sources said.

Markoff's parents, Susan Haynes and Richard Markoff, visited their son today in jail. Markoff's lawyer John Salsberg said on their behalf that they love their son very much and support him. Later, Markoff's brother also visited him.

Markoff was moved to a suicide watch because "shoelace marks were found on his neck," law enforcement sources said.

Jail sources described to ABC News the sequence of events that led to Markoff's isolation from the other prisoners:

Upon his arrival at the jail, other inmates taunted him by calling, "Yo, Craigslist."

"He was nervous," one of the jail sources said. "He didn't want to be in general pop[ulation]."

At around 11:45 a.m. Thursday, deputy sheriffs discovered the shoelace marks on his neck -- the leather loafers that he wore at time of arrest having been taken away because they had hard soles.

The shoelace marks were viewed as a "suicide attempt," a source said, and he was moved to the "shu unit" -- a segregated unit -- where he was issued a paper gown and was to sleep on a cot without sheets or blankets, just a bare mattress.

"I am deeply concerned for Philip's well being and I have complete faith that the sheriff's office will take care of him," Salsberg said.

He added that the transition for any individual from civilian life to prison life is extremely hard and Markoff's experience is no exception.

Cops Building Case

Police say Markoff killed Brisman April 14 in an upscale Boston hotel and robbed at least one other woman in Boston after binding her with plastic ties.

Markoff's fingerprints were found on the plastic ties used on one of the victims and in the room where Brisman was killed, police sources told ABC News.

A law enforcement source close to the investigation told ABC News that officers recovered a semi-automatic handgun and panties belonging to Brisman in the Quincy, Mass., apartment Markoff shared with his fiancee. The gun and panties were hidden in a copy of the popular medical school textbook "Gray's Anatomy."

The gun found inside Markoff's apartment is a forensic match to casings on bullets used to shoot and kill Brisman, ABC News has learned.

In addition, investigators said the plastic restraining ties used in an attack at a Holiday Inn Express in Warwick, R.I., -- on a woman who had advertised "erotic services" -- exactly match plastic ties found in Markoff's apartment.

In a twist, however, Warwick Police Chief Col. Steve McCartney told ABC News that the woman who was robbed in the Holiday Inn Express was reluctant to cooperate with the investigation.

'Phil, Get Off Me'

The developments in the case were disclosed amid a published report Thursday on Markoff's past interaction with a female friend.

Morgan Houston said she had a close call with Markoff, one of her study buddies when the two attended the State University of New York at Albany, after a night of partying four years ago.

"In a doorway, he pushed me up against the wall and tried kissing me," she said in a New York Daily News video. "I was trying to push him away, saying, 'No Phil, get off me.'"

Houston said she wasn't strong enough to push Markoff away, but that a mutual friend came to her aid.

"He had to physically pull him off me," Houston said.

Houston said it was the only time Markoff was aggressive toward her.

Markoff's Gambling Ties

As news of the evidence trickles out, a profile is emerging of the man police believe attacked and robbed women he met through Craigslist to pay off his gambling debts.

Police have said Markoff's finacee, Megan McAllister, who has stuck by him and not said much publicly, was accustomed to a lavish lifestyle that may have been financed, at least in part, by the money he got from robbing other women.

The couple's wedding Web site has been taken down.

McAllister's father said his daughter is coping with the help of friends, and that she knew nothing of the alleged crimes.

Markoff's high school yearbook paid homage to his penchant for gambling. As a senior, he wrote, "I bequeath my poker playing skills to Andy Finley so he won't lose his dad's house."

At his high school in Sherrill, N.Y., Markoff joined the bowling team, played golf and was even active in the school's "youth court." His former English teacher said she was stunned when she saw Markoff had been picked up for the arrest.

"I saw his picture and that beautiful smile. I knew it was Phil," Sonja Hluska told "Good Morning America." " I just couldn't believe it was Phil. He was a bright student, so friendly, polite, teacher's pet."

"I thought it would be some derelict," she said. "Not this young man, because he's just such a good person."

ABC News has learned that Markoff and McAllister had reservations to stay at the Foxwoods Casino this weekend, the same casino where he reportedly won $5,300 just two days after Brisman was murdered.

Markoff was arrested Monday during a traffic stop, en route to Foxwoods with McAllister in the car, law enforcement officials told ABC News. Sources told ABC News he had scratches on his body at the time of his arrest.

Other Potential Victims?

Police have asked anyone who may have been contacted by Markoff via Craigslist to come forward, and law enforcement sources told ABC News that detectives investigating the case are now fielding calls from other potential victims.

Should Craigslist Section Be Shut Down?

Connecticut Attorney General Richard Blumenthal is calling for the erotic services portion of Craigslist shut down, something other state officials across the country have also started looking into.

"We have a responsibility to protect children and women and anyone who may be victims of these kinds of criminal activity that may involve human trafficking, child exploitation other brutal and violent crime," Blumenthal said.

In an interview with the Boston Globe, Craigslist CEO Jim Buckmaster denied the site offers sex-related services, despite the "erotic services" portion. Police said that's where Markoff found all of his alleged victims.